Tungsten Grey AR-15 pistol kits, 7.5″ or 10.5″ barrel length, 5.56 NATO or .300 Blackout, chrome moly M4 barrel with nitride finish, 1/2×28 thread, 1×7 twist. Keymod or M-LOK handguard in standard, house, window, or riveted styles. Each kit includes the barreled upper, BCG, charging handle, mil-spec lower parts kit, pistol buffer tube with buffer/spring, A2 flash hider, and gas system — lower receiver and pistol brace are not included.